Expansive rotary underreamer



J. T. BARKELEW Filed Nov. 19, 1929 EXPANSIVE ROTARY UNDERREAMER Fel.V 24, 1931.

Patented Feb. `241,` 1931 Unirse STATES PATENT OFFICE ,Innes T. BaR-KELEW, or caseinENA,` centenaire, n ssrenoa To Joins enfiler, oF Los ANGELES, oALinonNIA @Xreaslve weer tweetallen nppiicatiqn'nei november 1e, iaaa semi no. 408,259.

This invention "has to do withexpansive reaming tools such: as underreamers of the type used in rotary drilling operations; and a general object oftheinvention `is the provision of an extremelysmple orm of expansive underreamer, or expansive reamer, having a minimum numberof parts and of extreme solidity of design.`

he present invention utilizes the slotted tubular body such as is shown in the Brown Patent No. 1,454,843,1issued May 15, 1923 and in `several subsequent i patents,` such for instance as that to JohnT. Phipps, No. 1,678,- 973, issued July 211, 1928. Expansive underit. `reamers or reamers of the typeshown in those patents utilize an interiorabutment mandrel for core against Whichtthe cutters .or cutter blocks bear inwaidlyfr support and along which the lcutters or cutterblocks ride in E3 relative longitudinalLverticalfmovement in order .to be givenftheir expanding and contracting movements.` y

The present invention, among other things, eliminates a central abutment mandrel or :525i core and substitutes an arrangement whereby the cuttersorcutter blocksbear inwardly directly against each other. The parts ofthe 4cutters or zcutter blocks which are interior ofthe slotted tubular body are so Si; formed that, by relative longitudinal movenient between the respective cutters, contraction and expansion iis obtained. This relative longitudinal movement is obtained in the specic design herein described by making 5.3 :one oi? Athe cutters longitudinally movable "in the supporting body,j while the other opposite cutter (speaking of au` underreamer which, 4in this ,particular illustrative embodiment, has .but two cutters)remains longii3 tudinally stationary in the body.

The cutters or `cutter ablocks- `are so` designed, as to their ,parts interior of the slotted tubular body, that, .when .the cutters are expanded, these parts substantially Acomplete- -lyillthe interior ,cross-section oifthe tubular body; thus, in effect, making `a body and ,out`

ter assembly which is solid and `,therefore .presentsmaximumlresistanceito inwardly di'- vrected forces. Andthis samedesign strong'- 513 y supports the cutters against `being .tem

out by tangential forces. Thus the invention achieves the solidity and rigidness of dcsign previously reached, but with fewer parts.

A better understanding of the invention will be had from the following detailed'description ofan illustrative embodiment, reference for this purposevbeing had to the ac ,y

`co i'npai".ying drawings, in which:

iigure 1 1s a,verticallongitudinal section showing the tool in its expanded condition;` .L

Fig. a similar view showing `the om Contracted; i i

`Figs. 3 and Al are cross-sections, respectively, on lines lsand .4r-Ll of Fig. 1;

`llig. 5 is a cross-:section on line 5-`-5 of Fig, 2," i

i Fig. 6` is a `reduced side elevation showing one side of the tool; and

Fig; 7 is Ta similar elevation showing the opposite side of the tool.`

In the drawings a typical. tubular slotted body is shown at 1() adapted at its upper cnil for `connection with a sub 11 for connection with the drill pipe, and provided with cutter slot-s 12 and 13. In the present showing "a reamer of tivo cutters only is illustrated, and so,correspondingly, there are buttwo cutter slots through the body wall.` Une of these cutter slots, is preferably just long enough to accommodate the relatively stationary i cutterelement 11i; `while the other cutter slot, 13, is longer, so as to allow its cutter element 15 a liinitcd vertical movement with relation to cutter element 14, c

Gutter elements 14 and 15 may he designed and constructed in any form desired and with vany suitable form of ultimate cutting edge `or cutter proper. In the form here shown,

lie,

blocks) with each other and with the body.y

Each of the cutter blocks 16 and -17 has, within the tubular body, an enlarged part .which bears outwardly against the body wall 'wh'en the vcutters are expanded (see Figs. 3A

and and which preferably is substantially seiniscylindric inform. These enlarged )arts are desinated frenerall br the nul e e .Y

morals 16aand 17o inycross-sectionall views.

.A These'inner enlarged parts not only extend' laterally beyond theextent of those parts the cutter carrying lugs 119) whichextend throughfthe body slots, butltheyV may also preferably extend above and below the cutter carrying lugs 19 sov as to provide outwardly facing shoulders 2O at the upper and lower ends ofV the cutter blocks, which shoulders also may bear outwardly against the body .wall for additional solidity. Such upwardly Vand outwardly extending shoulders may,

however 'be omitted asgthe lateral extent of V the inner block parte 16al and, 17u .may be Y ample and 'suflicient for outward bearing. ln

any case,'fs'uch shoulder is shown as omitted at the lower endof the cutter vblock 17 (the right hand cutter block in the drawings) for thefreason that when this cutter is up and expanded, the cutter slot 13 extends below the vlower end ofthe cutterelement, anda downwardly extending and outwardly bearv ing shoulder would not at that point bear Voutwardly against-the solid, unslotted, portion of the body wall. l V ,f

y The inner parts 16avand-17a of the respective cutter blocks meet each other lon vertical planes whichare so formed as to vgive relative expansive movements to the two cutter elements when the cutter element 15 moves upwardly. In order to obtain such expansive movement by a relatively short vertical movement, an-d also to obtain solid bearingv of the cutter blocks on eachother when expand-l ed and to Vso support the cuttersthat lcutter element 15 cannot-be forced downwardly by inwardly directed pressure however large, and further in order .to provide that the outward pressure-of the cutter elements against the casing when collapsed shall not be too great, these vertical planes of interaction be tween the two cutter blocks are stepped horizontally in thev manner illustrated. Thus `the cutter block 16 has a vertical rear surface v which vextends from. its lower end up- 'wardly to appoint near. its upper end where the cutter block 16 has an inward projection or expanding lug defined by the diagonal expandingsurface 27 and the vertical bearing surface 29, which surface 29 is situated inwardly of the plane of the" bearing surface Correspondingly, cutter block 17 has a vertical bearing surface 26 which extends from itsupperend downy to a point near the lower end of that cutter block, at which 'point the cutter block 17 has an expanding lug f which is 'defined by the d.iagonal` expanding the position of Fig.

surface 28 and the offset vertical bearing surface 30. ln the expanded-position of the cutter eleinentsthe lower vertical odset bearing face 30 of cutterblock 17 bears upon the lower part of the'vertical bearing surface 25 of cutter block 16; whiletheuppervertical offset bearing face 29 of Vcutter block l16 bears upon the upper part of bearing face 26 of cutter bloc-l.; 17. Thus in this expanded position the two bearing faces25'and 26 of cutter blocks 16 and 17, respectively,are spaced apartl a short distance, the distance of their spacing representing theainount of diainetral expansion of the tool." Y

When the cutter element 15 is moved downwardly its lower expanding lug, delined by `the 'faces28 and 30, moves below the lower of thecutterv blocks', the two vertical bearingy .faces 25 andf26' areink contact, or substantially so.v All this will be readily understood `from a comparison of Figs. land 2.

- Acutter propeller in .thefforin4 of a plunger is located .within thebody below. the lower end'ofcutter block 17 andpresses 'upwardly against that cutter block.- ACutter actuating spring 36vis confined in the-body below the propeller v35. This compression spring may be compressed and supported'at its lower end onl pin 37 of the tool joint at the upper .end ofthedrill bit 38 lwhich is usually attached' tothe lower end of expansive reainers or'underreamers. The spring action is constantly to.l press the plunger 35 upwardly, therefore constantly tending to elelyate the cutter element 15. Whenthe tool is not within a casing, and the cutters are :free to expand, the spring moves cutter block 17 up fronithc position of Fig. 2 to 4 1. -In so moving upwardly the pairs of diagonal expanding faces 28, 81 and 27 82 react upon each other as rather abrupt wedge faces, causing the Vcutter elements to move outwardly tothe relative expanded position .shown'in F ig. 1. Then, after outward expansive movement, the vertical faces 26 and SO'of cutter block 17'ride directly upwardly on the vertical bearing faces 25v and '29,V respectively, of cutter block. 16, so that in the final expanded position the. cutters'are solidly supported against inward: pressures. At' thesame time that the cutters'and their cutter blocks reach the expanded position of, Fig. 1.-. their inner enisa i theother being longitudinally movable in its slot, they twojcutterjelements being in contact with each other within the body, and the surfaces of Contact being formed so that the cutters are moved outwardly by'virtue of relative vlongitudinal.movement o'lj the movable cutter in onel direction. Y

yfaces ot'` contact -being ormedso that the cutters are moved outwardly by virtue of relative upwardlongitudinal movement of the mov- Vable cutter. y

4.' In an expansive roaming tool', the combination of a tubularslotted body, cutter elemens' :mounted in the body slotsjfor outward and inward movements oi expansion' and contraction, vone yoli' the cutter elements being longitudinally immovable in its body slotand vthe other being longitudinally movable in its slot, the two cutterelements being in contact with each other 'within the body, and the surfaces of contact beingltormed so that the cutters are moved outwardly by virtue of relative upward longitudinal movement otthemovable cutter.

5. In an'eXpansivereaming tool, the-combination` of a tubular slottedjbody, cutter elements mounted in the body slotsfor outward and inward movements of expansion and contraction, one of the cutter 'elementsbeing movable longitudinally with reference tothe other, the cutter elements having laterally enlarged parts lwithin the tubular body, which parts bear inwardlyagainsteach other and together substantially ll the body interior,y the surfaces of contact of said parts being so formedthat the cutters are moved outwardly by virtue of relative longitudinalmovement of themovable cutter in one direction.'v

6. In an expansive reaming tool,.the combination of a tubular slotted'V body, cutter elements'mountedin the .body slots for out-- ward and inward movements ot 'expansion and contraction, one of the lcutter elements being longitudinally immovable in its body slot and the other being longitudinally 'movable in its Vslot, the cutter elements having laterally enlarged partsr within the tubular body, which parts bearinwardly against each other and together substantially the body interior, the surfaces of Contact of said yparts being so formed that the cutters are moved outwardly by virtue of relative longitudinal movement jot the movable cutter in one direction.

7. In an 'expansive reaniing tool, the com.- bination of a tubular slotted body, cutter elements mounted' in' thebody'sl'ots. for outward Y upwardly. Y

and inward movements of' expansion and contraction, one of the cutterV elements being movable longitudinally with reference to the other, the cutter elements having laterally enlarged' parts within" the ltubular body,

whichparts bear inwardly against each other and together substantially lill the body interior,'the surfaces or" contactot said parts being so formed thatthe cutters are moved outwardly by virtue of relative upward longitudinal movement of the movablecutter;

' 8. YIn an expansive roaming tool, the com'- bination of* altubular slotted body, cutter relement-s'mounted in thebody slots for voutwardfand inward movements of expansion and contraction, 'one ofthe cutter elements being movable longitudinally-mits body slot and the other being vlongitudinally movable 'in its slot, the cutter elements having laterally'enlarged parts within the tubular body, which parts bear inwardly against each other and together substantiallyill the body interior, kthe `surfaces of Vcontact of said parts beingl so 'ormedthat 'the-cutters are moved outwardly by virtue-of relative upward longitudinal movementof'the movable cutter.

Y 9. Inl an'eXpansive reaming tool, the combination of a tubular slotted body, cutter elements mounted in the body slotsfor outward and inward movements of expansion and contraction, one ot the cutter elements being movable longitudinally withreference `to the other, the cutter elements being in f contact with each other within the body,thev surfaces of contact being ormedso that the cutters are moved outwardly by virtue of relative upward longitudinal movement ofthe movable cutter, land means within the body 'tending to move said movable cutter upwardly.

- 10. In an expansive reaming tool, the combination of a tubular slotted body, cutter elements mounted in the body slots for outward and inward movements of 'expansion and contraction, one of the cutter elements 'being longitudinally immovable in its body slot and the other being longitudinally movable in its slot, the two cutter elements'being in contact with each other within the body, the surfaces. of contact being formed so that the cutters are moved outwardly by virtue of relative upward longitudinall movement of the movable cutter', and means'within the body tending to movek said movable cutter 11. In an expansive reaming tool,the combination of a tubularl slotted body, cutter elements mounted in the body slots for outward and inwardv movements of expansion and contraction, one of the cutter elements being movable longitudinally with reference to the other, the cutter elements having laterally enlarged parts within the tubular body, which parts bear inwardly against each other yand together substantially lill the body interior, theV surfacesofcontact of said llO parts being so formed that .the cutters are -movedoutwardlyby `virtue of relative longitudinal movement of themovable cutter in one direction, and means within the body if; tending to `move said movable cutter upr wardly.

l2. In an expansive reaming tool, the combination of a tubular slotted body, cutter elements mountedin the body slots for outward `andmward movements of expansion and contraction, one of the cutter elements being longitudinally immovable inits body slot and the other `being' longitudinally movable in its slot, the cutter elements having laterally enlarged parts within the tubular body, which parts 4bear inwardly against each other and together substantially fill the body interior, the surfaces of Contact of said parts being so formed that the cutters are moved outwardly by virtue ofrel'ative upward longitudinal movement oi the movable cutter in one direction, and means withinthe body tending V to move said lmovable cutter upwardly.

13. In an expansive reaming tool, the combination of a tubular slotted body, cutter elements mounted in the body slots for outward and inward movements of expansion and contraction, the cutter elements bearing against each other within the body, one of the elements being longitudinally movable relativey ly tothe other and their surfaces of contact vbeing so formed that the cutters are moved outwardly by virtue of relative longitudinal movement of the movable cutter in one direction, both cutter elements having a casing engagingpart, and said part of the relatively movable element being longitudinally spaced from said part of the other element so as to be engaged first by a casing into which the tool is moved.

14. In anexpansive reaming tool, the combination of a tubular slotted body, cutter elements mounted in the body slots for outward and inward movements of expansion and contraction, one of the cutter elements being longitudinally immovable in its body slot and the other being longitudinally movable in its slot, the two cutter elements being in contact `with each other within the body, the surfaces of contact being formed so that the cutters are moved outwardly by virtue of relative upward longitudinal movement of the movable cutter, the movable cutter element extending upwardly in its slot, when the cutters are ei;- panded, to an elevation above the upper end of the other cutter and having at its upper enda casing engaging shoulder which is engaged by a casing before the other cutter is engaged. f

15. In an expansive roaming tool, the combination of a tubular slotted body, cutter elements mounted in the body slots for outward andinwar'd movements of expansion and contraction, one of the cutter elements being lon- .1 gitudinally immovable in its body slot and per end a casing engaging shoulder which is engaged by a casing before the other cutter is engaged.

In witness that I claim the foregoing I have hereunto subscribed my name this 15th day oi November, 1929.

JAMES T. BARKELEVV. 

